Ulusi wamtundu wa kuwala umatanthawuza mchitidwe wogwiritsa ntchito zokutira zamitundu kapena zolembera pazingwe ndi zingwe kuti muzindikire mitundu yosiyanasiyana ya ulusi, ntchito, kapena mawonekedwe. Dongosolo la zolembera izi limathandiza akatswiri ndi oyikapo kusiyanitsa mwachangu pakati pa ulusi wosiyanasiyana pakuyika, kukonza, ndi kuthetsa mavuto. Nayi chiwembu chodziwika bwino chamitundu:
Mu GL Fiber, zizindikiritso zamitundu zina zimapezeka mukapempha.